Devil Trigger

The Devil Trigger (often abbreviated as DT) is a special technique possessed by demons and half-demons which allows its user to release their demonic side. While in Devil Trigger, the user will assume their true, demonic form. In this form, many of the character's attributes are amplified, and the character may have access to upgrades or even additions to their normal abilities like flying or hovering. When playing on higher difficulties, enemies can enter a Devil Trigger-like state after a certain time limit (which is fixed for each enemy). This causes enemies to strengthen their attributes as well as making them attack more often and more powerfully.

Recurring features
While in Devil Trigger, the characters' speed and strength increase, and they constantly recuperate vitality. Additional effects are apparent, though these vary between games, and are usually determined by the equipped weapons or items of the character. For example, Dante will usually gain the ability to hover while in Devil Trigger, but this is obtained by equipping the Alastor in Devil May Cry, the Aerial Heart in Devil May Cry 2, and Nevan in Devil May Cry 3.

Devil Trigger is confirmed to be available to Dante, Sparda, Lucia, Trish, Vergil and Nero. Several other characters, specifically Arkham, Credo, Agnus and Sanctus have abilities resembling Devil Trigger, though it is not known if it is the same.

In Devil May Cry 3 and Devil May Cry 4, activating Devil Trigger causes enemies to take damage and consequently interrupt what they were doing. In Devil May Cry 3, the explosion can be charged by holding down until the chosen number of Devil Trigger runes glow, and then releasing the button. Interestingly in Devil May Cry 4, Dante's DT activation doesn't deliver any damage. Also, when activating Devil Trigger, the character is granted temporary invincibility.

In all games excluding the second, it is possible to unlock "Super" versions of the playable characters. Among other effects, these versions possess unlimited Devil Trigger, thus allowing the player to stay in demon form indefinitely whilst taking advantage of the higher damage output and exclusive attacks. However, this reduces the mission rating by a certain percentage when used.

Devil Trigger Gauge
The Devil Trigger Gauge shows how much demonic energy you have. The energy is mainly used for Devil Trigger and is slowly drained all the time while in devil form. The Devil Trigger Gauge can be seen below the Vitality Gauge as a group of runes. In the beginning it consists only of three runes, but can be extended by buying Purple Orbs. The amount of time the user can stay in Devil Trigger is determined by the length of the Devil Trigger Gauge and Devil Trigger cannot be engaged unless the first three runes are filled. The capacity of the Gauge can be increased by purchasing Purple Orbs.

Some moves in Devil Trigger also deplete the gauge (eg. Stinger and Kick 13). The gauge can be replenished by using Devil Stars, and, in Devil May Cry 2, by standing on special platforms.

Several moves and Items also cause depletion of the gauge. The Bangle of Time and Quicksilver Style stops or slows down time for enemies, but constantly reduces the DT gauge while using it. Also, the Doppelganger Style slowly drains the gauge when you use the style's moves. In addition, Vergil, whenever he uses multiple Summoned Swords at one time, also causes his Devil Trigger Gauge to deplete.

Enemies
On the hardest mode in all games, Dante Must Die, enemies can use Devil Trigger. They enter the state after a set time from the start of a fight, and this time is specific for each demon. Usually in this form they deal more damage, have more health and are harder to knock off.

In Devil May Cry 3 the aim in Mission 6 is to overcome three trials of the Temen-ni-gru, the Trial of Wisdom, the Trial of Skill, and the Trial of the Warrior. The latter will consist of a long fight with demons in their Devil Trigger state, no matter the mode. However, their Devil Trigger can be temporarily disabled by unlocking seals on the walls.

In Devil May Cry 4, demonic bosses have a "desperation mode", similar to Devil Trigger, when they are low on health. However, it seems to be something separate from normal enemy Devil Trigger, as it appears on all modes. Effects of it vary for each boss. For example, Echidna starts to glow a bright gold aura, her "dragon phase" becomes vulnerable for a timed Buster and she starts throwing her seeds around during several moves. Bael turns purple/red, and his ice starts to regenerate faster when destroyed.

Dante
Dante's exact Devil Trigger form changes throughout the series, though it seems to resemble his father more strongly as the series progresses. In Devil May Cry and Devil May Cry 3, the appearance of the Devil Trigger form is dependent on the Devil Arms the character is wielding at the time of assumption, while in other games the character will possess one or two default forms. For more informations on how Dante obtains Devil Trigger and detailed differences in each game, see below.

In Devil May Cry 3, Dante gains his Devil Trigger after his first fight with Vergil. During the battle, Vergil stabs Dante with the Yamato, and then with the Rebellion. After Vergil leaves, Dante's demonic power awakens, transforming both him and the Rebellion. Dante's demonic form is quite humanoid, though it possesses a demonic face and red, scaled skin. Its exact features, generally its cranial crest and the fins on its back, vary with the weapon it has equipped. When using the Rebellion or Nevan, the fins actually serve as wings, allowing flight. Dante can also use the Doppelganger Style in conjunction with his Devil Trigger, allowing him to generate a shadowy clone of his demonic self.

In Devil May Cry, Dante cannot use his Devil Trigger until he obtains his first Devil Arm, the Alastor. Unlike in Devil May Cry 3, his demonic forms are replicas of the fully matured form of the demon whose power he is channeling—Alastor, Ifrit, and even Sparda. However, although his demonic aura manifests in Sparda's form at several points in the story, he is not able to use Devil Trigger with the Sparda until he goes up against Mundus.

In Devil May Cry 4, Dante is able to transform into his demonic form at his very first appearance, in which he is attacked by Nero, and it is unaffected by the weapon he has equipped. This demonic form is very reptilian, but the fins on its back cannot be used as wings, and are still shaped much like an insect's wings.

In Devil May Cry 2. Dante can transform into his demonic form from the beginning, and it is also unaffected by the weapon equipped. However, he can modify its abilities using the Amulet. Although this demonic form has a more matured appearance compared to the one used in Devil May Cry 3, it has not quite reached its final state. However, Dante can sometimes access that state, his Majin Form, if he activates his Devil Trigger while at critical health. Dante's Majin Form strongly resembles his father's demonic form, as well as his brother's "Nelo Angelo" form, but its wings are reptilian, rather than insectoid.

Vergil
Vergil's Devil Trigger is first seen during his second battle with Dante, in the Lair of Judgment, although in the Special Edition, it is usable from the beginning. Like Dante's, Vergil's demonic form retains the same basic shape of a blue, reptilian humanoid, with minor variations depending on the weapon equipped.

After being killed by Mundus and having his body possessed, Vergil's Devil Trigger changes a demonic knight named "Nelo Angelo". This form more strongly resembles that of his father, Sparda, though it seems to consist of actual armor and a red mantle, rather than the tough carapace that Sparda possesses.

Nero
Nero, the main protagonist of Devil May Cry 4, also receives a Devil Trigger. He gains his Devil Trigger in Mission 6 after defeating Agnus. While Nero demands for answers from the scientist, Agnus’s servants, Bianco Angelos catch him unaware and impale him with their lances. Agnus then tells Nero of his plans to him, and stabs him once more with a Gladius. Nero almost fades away, but suddenly remembers a moment from his past. Kyrie was endangered, and Nero, in despair, cried to her. He awakens, takes Yamato, and enters DT state.

When activated, it seems to appear as a translucent shadow of a demon that encompasses his body. Nero's Devil Trigger grants him the assistance of this demon that forms behind him while in Devil Trigger state, who mimics Nero's every attack with Yamato. However, as Nero, you cannot use Yamato unless you are in Devil Trigger.

Others

 * Lucia transforms into an angel-bird hybrid, with her whole body covered with white feathers. She is able to shoot these feathers as a ranged weapon, several at once.
 * Trish doesn't change her appearance, but assumes a golden aura. She also puts on her sunglasses.
 * Secretary's DT is exactly like Lucia's, but is violet in color with a black body coloration, making her resemble a fallen angel, or at least a crow.

Items affecting Devil Trigger
The Haywire Neo-Generator from Devil May Cry 3 causes Dante to constantly lose his Vitality in exchange for an infinite Devil Trigger, but cannot be turned off. The Untouchable from Devil May Cry causes the player to become invulnerable while putting him into DT state for a short period of time.

Trivia

 * When in Devil Trigger state, the characters' voices become deeper and more demonic.
 * Both Dante and Nero receive their Devil Triggers after being impaled and forced to remember when their loved ones died or were endangered.
 * In Devil May Cry 4, Dante and Nero's Devil forms are unable to fly, although some of the concept artwork depicts both devil forms with wings. Instead, Dante can use the Pandora's "PF594: Argument" to hover.
 * The Devil Trigger forms seen in Devil May Cry 3 were designed by Kazuma Kaneko, a character designer for Atlus who designed the characters for the Shin Megami Tensei series. This was in due to having included Dante as a cameo in said series as Kazuma is a big fan of the Devil May Cry series.
 * The spirit of the Alastor sword/Devil Arm appears as blade master Alastor in Viewtiful Joe where he has his own Devil Trigger.
 * The Devil May Cry 4 artbook showcases a handful of concept sketches of Devil Triggers for both Dante and Nero. For the former notably includes both wings and a tail whilst the latter shows a full DT bodily form which bears many similarities to Vergil's DT form using Yamato includes a claw-like sheath on the arm and wing-like tailcoats.